Epicyclic roundabout



5 Sheets-Sheet 1 July 7, 1964 F. A. HRUBETZ EPIcycLIc RoUNDABoUT- Filed May l 1962 July 7, 1964 FQA. HRUBETZ 3,140,092

EPIcYcLIc RoUNDABoUT Filed May 1, 1962 l 5 sheets-sheet 2 INVENTOR.

FRANK A. HRUBETZ ATTORNEY July v'7, 1964 F, A, HRUBETZ 3,140,092

.EPICYCLIC ROUNDABOUT Filed May 1 1962 5 Sheets-Sheet 3 ATTORNEY July 7, 1964 F. A. HRUBE-rz 3,140,092

EPICYCLIC ROUNDABOUT Filed May l, 1962 5 Sheets-Sheet 4 07X I INVENTQR.

FRANK A. HRUBETZ ATTORNEY July 7, 1964 F. A. HRUBETz 3,140,092

EPICYCLIC ROUNDABOUT Filed May 1, 1962 5 Sheets-sheet 5 &

INVENTOR. FRANK A. HRUBETZ ATTORNEY United! States Patent 3,140,092 EPICYCLIC ROUNDABOUT Frank A. Hruhetz, 3495 25th St. SE., Salem, Oreg. Filed May 1, 1962, Ser. No. 191,634 4 Claims. (Cl. 272-36) This invention is in the general class of amusement devices and relates more particularly to a novel form of roundabout where the riders follow a planetary path of orbital movement resulting from the combination of two different circular motions.

The general object of the invention is to provide a new and improved form of roundabout that produces the illusion of high speed without being unsafe.

Other objects are to provide a roundabout wherein relatively high rotational velocities of the apparatus are utilized to produce slower resultant velocities of the riders thereby presenting a spectacular performance to onlookers without actually endangering the riders, to provide a roundabout of the type described that tips up to display the motions of its riders to spectators on the ground, to provide a roundabout of the type described which is relatively economical to manufacture and maintain, which is substantially noiseless in operation, which is entirely contained and transported on an automobile trailer and which can be readily disassembled for travel and reassembled for operation/by a few workmen Without lifting-or removing any heavy parts.

In the present roundabout a plurality of circular platforms having radial seatsfor riders are mounted for rotation on the arms of a spider frame which in turn rotates on one end of a tilting boom whereby the platforms are elevated and inclined after the riders have assumed their seats and the mechanism is put into operation. The platforms attain relatively high rotational velocities on their individual axes but each rider travels at a much slower velocity in an epicyclic path carrying him back and forth between different points on a circle having a diameter more than twice the diameter of the platform. The velocities of the riders and the acceleration forces acting on them along the epicyclic paths are therefore not abnormally high for such amusement devices whereby the apparatus is entirely safe and does not endanger the riders. The velocity ratio of the platforms and spider frame and the elevation and inclination of the revolving platforms produce variation in the epicyclic path causing the riders to swing back and forth between different high points and low points without repeating a uniform pattern. All the motions are controlled so that the riders are never subjected to haphazard or jerky movements which might be dangerous.

x A spectator on the ground,v however, does not perceive the act-ual epicycloidal path of travel of each rider. The impression received by the spectator is that the platforms rotate unusually fast and so` he naturally assumes that the riders themselves are traveling at high resultant velocities. Thus, the present device develops a high degree of spectator attraction and has more entertainment value for both spectators and riders than conventional roundabouts. The spectator interest is of additional benefit in generating more business for the roundabout whereas conventional roundabouts have less spectator appeal.

The present roundabout is especially adapted for convenient transportation for use in county fairs, traveling Carnivals and the like. The whole apparatus is mounted for operation on a highway trailer and is constructed so that the heavy members may be folded together compactly without lifting or taking them apart. The smaller partsare removable from the framework and are carried compactly on the trailer whereby the apparatus can be dismantled with facility after a days operation and moved during the night for operation the next day at a new location. The roundabout, including its power supply, is completely self-contained and does not require any special preparation or facilities at each location of use.

Additional objects and advantages will become apparent and the invention will be better understood with reference to the following detailed description of the preferred embodiment illustrated on the accompanying drawings. Various changes may be made, however, in the construction and arrangement of parts and all such modifications within the scope of the appended claims are included in the invention.

In the drawings:

FIGURE 1 is a longitudinal sectional view of the roundabout with parts broken away and parts removed, showing the boom in partially elevated position;

FIGURE 2 is a fragmentary enlarged plan view taken on the line 2-2 of FIGURE 1, showing the hydraulic system for lifting the boom;

FIGURE 3 is an enlarged fragmentary plan view showing the drive mechanism on the boom for the rotating platforms;

FIGURE 4 is a side elevation view of the main hub assembly on the boom with parts broken away;

FIGURE 5 is a side elevation view of the platform spindle and hub on the master spider boom with parts broken away;

FIGURE 6 is a top plan view of the roundabout with certain parts omitted;

FIGURE 7 is a top plan view of the roundabout in passenger loading position with the rotatable platforms shown in outline;

FIGURE 8 is a sectional View of a passenger loading ramp taken on the line 8 8 of FIGURE 7; and

FIGURE 9 is a diagram showing the epicyclic path of motion of a rider.

Referring rst to FIGURE l, the numeral 10 designates the frame of a semi-trailer having rear wheels 11. The front end 12 of this frame is equipped with the usual fth wheel connection (not shown) for attachment to a tractor vehicle in the conventional manner. After the trailer has been located at the site of operation, the landing gear or front legs 13 are lowered to the ground and the tractor vehicle is removed. The frame 10 is also preferably equipped with Outrigger legs or braces (not shown) bearing upon the ground on opposite sides of the frame to provide lateral stability for operation of the roundabout.

An elevating boom 15 has its rear end pivotally mounted at 16 on a horizontal axis at the rear end of trailer frame 10. Boom 15 may be pivoted upward to an inclination of about 30 by means of a hydraulic cylinder and piston unit, or ram, 17. The cylinder is pivotally connected at its lower end to a bracket 8 on the frame 10 and its piston rod is pivotally connected at 19 to an intermediate point on the boom 15. The boom 15 is arranged to retract to a horizontal position between the longitudinal frame members of the trailer and the trailer frame further includes a suitable support (not shown) for the front end of boom 15 in its horizontal position. The trailer is equipped with an auxiliary engine and a hydraulic pressure system as shown in FIGURE 2, with suitable controls for operating the lift cylinder 17 and also an electric generator for supplying the electrical power requirements of the roundabout. Since these features are conventional they are not fully illustrated.

The forward end of boom 15 carries a vertical tubular spindle 20, as shown in FIGURE 4, to support a spider frame 21. Spider 21 comprises a central bearing hub 22 equipped with upper and lower horizontal anges 23 and 24 for connection with the three spider legs 25, 26 and 27 shown in FIGURE 6. Each leg is a cantilever beam, or boom, supported by hub 22 on the spindle 20. The legs are preferably rigidly connected to hub 22 by pairs of removable pins 2S engaging the upper and lower anges 23 and 24. By removing one pin from each of two legs they may be folded together in the opposite direction from the third leg with all three legs aligned longitudinally with the boom 15 and frame 10 for transportation. By removing both pins from each leg, the legs may be detached from the hub, if desired.

The outer end of each spider leg is equipped with a vertical bearing 30 (FIGURE 5) and the three legs are braced to each other by three trusses 31 (FIGURE 6) in triangle configuration removably secured by pins to suitable brackets on the outer end portions of the spider legs. Spindle 20 is welded to boom 15 and hub 22 is equipped with internal bearings 18 to support the triangular spider frame 21 for rotation on the spindle.

A platform 40 is mounted on each spider leg 25, 26 and 27. Each platform comprises a hub 41 having a vertical spindle 42 to support the platform for rotation in the bearing 39 as shown in FIGURE 5. Mounted on the hub 41 are a plurality of radial cantilever beams 43 forming wheel spokes to support a removable circular sectional oor 44 as shown in FIGURE 3. The inner end of each beam 43 is pin connected with its hub 41 so that the beams may be disconnected from the hubs 41. On each circular floor 44 are mounted a plurality of removable radial bench seats 45 and around the edge of the platform there is mounted a removable guard fence 46, as shown in FIGURE 1, equipped with gates. Overhead are arranged decorative lights 47.

The platforms 40 and spider 21 are rotated by an electric drive motor t) mounted on the end of boom 15 as shown in FIGURES 1 and 4. This motor drives a shaft 51 mounted in bearings 52 inside spindle 20. The lower end of shaft 51 carries a pulley 53 connected by a belt 54 with the motor 50 through a speed reducer 50a. On the upper end of shaft 51 is a main drive sheave 55 driving a belt 56. Belt 56 drives a pair of sheaves 57 as shown in FIGURE 3 for rotating the platform 40 on the spider boom 25 which will be referred to as the main or master spider boom. Belt 56 is tensioned by a belt tightener sheave 5S.

Each platform 40 is equipped With a cylindrical rim 6i) whereby the three platforms are rotated by frictional engagement with four pneumatic rubber tired drive wheels 61, 62, 63 and 64. The wheels 61 and 62 are mounted on spindles 65. These spindles are mounted for rotation in bearings on the ends of arms 66 pivoted to opposite sides of the main spider boom 25. The tires are held in frictional engagement with the platform rim 60 by adjustable turnbuckles 67, one end of each turnbuckle being connected with one of the arms 66 and the other end being connected with spider boom 25. Belt tightener sheave 58 is similarly adjusted by a turnbuckle 68. One end of the turnbuckle is connected to boom 25 and the other end is connected to one end of a pivotal bell crank arm 69 which carries a spindle for the sheave 58 on its other end. Thus, the belt tightening means 68 is independent of the means 67 for adjusting the frictional driving engagement between wheels 61 and 62 and the platform rim 60.

Sheaves 57 are mounted on the upper ends of spindles 65 and other sheaves 70 are mounted on the lower ends of these spindles for driving a pair of belts 71. In order to effect this driving connection the wheels 61 and 62 and the sheaves 57 and 70 are all IiXedly connected to the spindles 65. The belts 71 are trained around sheaves 72 and 73 which carry the drive wheels 63 and 64. The sheaves and wheels are both Xedly connected to the spindles 73 and the latter are mounted for rotation in bearings in the ends of pivotally mounted arms 74 on the spider booms 26 and 27. The tires are held in frictional engagement with the rims 60 of the platforms on these spider booms by means of adjustable turnbuckle links 75. -The belts 71 also pass around belt tightener sheaves 76 carried by pivotal arms 77 on the spider booms. The

belts are tensioned by means of adjustable turnbuckle links 78. This arrangement of belts and rubber tired wheels provides a silent driving connection between the main drive sheave 55 and all three rotatable platforms 40.

The platform 40 on the master spider boom 25 rotates the spider frame 21. For this purpose the lower end of spindle 42 for this platform only is xedly connected with a sheave 80 carrying a belt 81 on the underside of the spider boom as shown in FIGURE 5. This belt is trained around a double sheave 82 which also carries a second belt 83, as shown in FIGURE 1, these belts being represented by broken lines in FIGURE 3. Belt 83 is trained around a large sheave 85 which is fixedly mounted on the stationary main spindle 20 as shown in FIGURE 4. Belt 81 is tensioned by a pair of take-up idler pulleys 86, and belt 83 is tensioned by a take-up idler pulley 87, both being adjusted by turnbuckles as previously described. Thus, the rotating sheave 80 is belted indirectly to the stationary sheave 85 whereby rotation of the former with its platform 40 causes the spider frame 21 to be rotated around the main spindle 20. The purpose o'f double sheave 82 is to avoid the excessive length of a single belt extending the entire distance between sheaves 80 and 8,5. Idler take-up pulley 87 has been omitted in FIGURE 3 in order to clarify the belt arrangements.

The various belts have been referred to in the singular, although in practice each belt is preferably a plurality of belts as shown in the drawings in order to handle the power requirements of the apparatus, the sheaves for' such belts having multiple grooves for the number of belts which are necessary in each instance.

A brake drum 90 is xedly connected to the spider main hub assembly 22 as shown in FIGURE 4. This brake drum is engaged by a brake band 91 having an operating mechanism mounted on the stationary sheave 85.

A hydraulic unit 93 for raising the boom 15 is shown in FIGURE 2. This unit comprises a reservoir 94, motor 95, pump 96 and valve 97 operable by a control rod 98. The valve controls the ow of hydraulic fluid from the pump to a conduit 99 leading to the hydraulic cylinder 17.

The apparatus is operated from a control station a short distance from the trailer. FIGURE 1 shows connections on the rear end of the trailer having a rod from the control station for operating the valve rod 98 and a ilexible cable 121 for tightening and releasing the brake band 91. The control station also has a start and stop switch for energizing and deenergizing the power cable 122 for the motor 50. Thus, an operator at the control station may start and stop the rotation of the apparatus and may lift and lower the boom 15.

FIGURES 4 and 5 show provision for establishing electrical circuits for the lights 47 in FIGURE 1. Three metal slip rings are insulatedly mounted at 125 on stationary sheave 85. These slip rings are energized from any suitable source of power such as a generator driven by an internal combustion engine on the trailer.- This generator may also supply power for the rotating motor` 50 and the hydraulic pump motor 95. Brake drum 90 which rotates with the spider frame 21 carries three brushes 126 engaging the slip rings 125. Power cables extend from these brushes along the three booms 25, 26 and 27 of the spider to the outer ends thereof where each cable connects with three brushes such as the brushes 130 in FIGURE 5. These brushes make electrical contact with three slip rings 131 insulatedly mounted on platform hub 41. A flexible connector cable 132 is equipped with a connector fixture 133 for energizing the light circuit on the individual platform 40. When the apparatus is dis mantled each platform circuit may be disconnected at 133.

FIGURES 7 and 8 illustrate the provision for riders to enter and leave the platforms 40 when the boom and platforms are in horizontal position. The spider frame 21 carries a center deck which slightly overhangs edge portions of the three platforms 40 and covers the driving wheels 61-64 and belts 56 and 71. Upper stair sections 141 are mounted on the spider frame in the three spaces between the platforms 40 to revolve with the deck 140 and the spider frame. Portable stair sections 142 are placed on the ground in suitable position to lead up to the upper stair sections 141, preferably on opposite sides of the trailer and at one end thereof. The operator stops the rotation of the spider frame so that the upper stair sections register with the positions of the lower stair sections.

The upper stair sections are detachable from the spider frame when the apparatus is dismantled for transportation and all such detachable parts are carried on the trailer. The main boom 15 and spider frame booms 25, 26 and 27 are not detached for transportation.

All three platforms 40 rotate in the same direction and at the same speed whereby all the riders follow substantially identical epicyclic paths of movement if the paths are plotted from the same starting point. A typical path of movement is illustrated in FIGURE 9 for the rider R at the outer end of one of the seats on one of the platforms, the other two platforms being omitted in this figure. The platform rotates in a clockwise direction about the axis of its spindle 42 as indicated by the arrow 100. At the same time, spider 21 rotates counterclockwise about the axis of boom spindle 20 as indicated by arrow on circle 101.

The shape of the epicyclic curve depends upon the ratio of the radial distance of the rider from the center of his platform to the length of the spider arm and the driving ratio between the sheaves 80 and 85. In the illustrated embodiment the first ratio is as illustrated in the drawings and the second ratio is preferably about .6 to 1. The driving speed is preferably such as to rotate the platforms 40 about 21.6 revolutions per minute in one direction while spider 21 rotates 12.9 revolutions per minute in the opposite direction. Obviously, the invention is not limited to these particular ratios; the ratios may be varied as desired to change the shape of the epicyclic curve and the driving speed may be varied as desired within the maximum safe limit for the riders.

In the present example, the rider R accelerates rapidly at the beginning of his movement along the path 102 and then decelerates as he approaches the point 103. At point 103 the rider is substantially stationary for an instant prior to a second phase of acceleration and deceleration along the path 104 as he approaches the point 105. These phases or minor cycles are repeated, taking him next along the path 106 to point 107 and thence along the path 108 to point 109, these paths all being plotted on a stationary reference plane such as the ground.

An advantage of the present combination of ratios to produce the described paths of movement is that the rider never returns immediately to any previous point of reversal on circle 101. This lends variety to the movement when it is remembered that after the rotation is started, the boom 15 is elevated to incline the plane of rotation of the riders. If the rider R is traveling upwardly in path 102, he will be traveling substantially horizontally in path 104, downwardly in 106 and upwardly again in 108. These paths resemble hypocycloidal curves but are not true hypocycloids with the ratios stated above.

Thus, his successive paths of movement zigzag in different directions across the outer imaginary circle 101 connecting the reversal points at the cusps of the epicyclic curve. It will be apparent that in the present diagram a considerable number of excursions would be made back and forth across this circle before the rider would again return to this starting point. Each path 102, 104, 106 and 108 is roughly a chord of the circle 101 and is approximately equal to a diameter in length. This provides a long excursion relative to the diameter of platform 40.

Although the rider does not move at a dangerous speed along the paths 102, 104, etc., relative to the ground, he

is moving very fast relative to adjacent riders on the near sides of the other two platforms which are moving in an Opposite direction. Spectators on the ground also get the impression that the rider is traveling at very high speed because both the platform and the spider are rotating much faster.

This apparent paradox is explained by the fact that a considerable part of the time the point on platform 40 which is occupied by the rider is rotating directly counter to the direction of the movement of the spider whereby all parts of the apparatus are in rapid motion even at the very instant when the rider is stationary relative to the ground. For instance, at the beginning of movement along path 102, the two components of motion are opposite in direction and approximately equal in magnitude. This phenomenon occurs at each cusp 103, 105, 107 and 109. The performance of the roundabout is therefore a spectacular thing to watch as it seems to subject its riders to abnormally high velocities and abnormally high accelerations in changing direction, whereas in fact it does not. The position of hinge 16 is such that when the ride is tipped the lower peripheral portion of each platform 40 in turn approaches the ground level, thereby adding to the sensation because of this proximity.

Another important feature and advantage is that the riders are reciprocated back and forth without any reciprocating or reversing movements of the structure whereby large stresses are not developed in the apparatus. Except when the ride is starting up or slowing down, the platforms and spider frame always rotate at constant velocity.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

l. A roundabout comprising a horizontal boom mounted for pivotal movement in a vertical plane, a vertical spindle on the free end of said boom, a spider frame having radial arms connected to a central hub on said spindle for rotation in 'a horizontal plane, a circular platform mounted on each of said arms for rotation in a horizontal plane about the center of the platform, seats for riders mounted around the peripheries of said platforms, means for raising and lowering said boom to shift said spider frame and platforms between horizontal and inclined positions, a drive shaft in said spindle, rubber tired wheels driven from said shaft and engaging the peripheries of said platforms for rotating the platforms, and means driven by one of said platforms for rotating said spider frame.

2. A roundabout as dened in claim 1, including means on said spider arms for mounting said wheels, and means on said spider arms for holding said wheels in frictional driving engagement with said platforms.

3. A roundabout as defined in claim 1, including a motor on said boom driving the lower end of said shaft, a sheave on the upper end of said shaft, sheaves on said wheels, and belts on said sheaves for driving said wheels.

4. A roundabout as dened in claim l, said means for rotating said spider including va stationary sheave on said spindle, a sheave connected with one of said platforms, and belt drive means between said sheaves.

References Cited in the le of this patent UNITED STATES PATENTS 1,262,687 Miller Apr. 16, 1918 1,799,409 Custer Apr. 7, 1931 2,259,691 Harris Oct. 2l, 1941 2,319,327 Johnson May 18, 1943 2,847,216 Courtney Aug. 12, 1958 FOREIGN PATENTS 538,447 Belgium Nov. 25, 1955 

1. A ROUNDABOUT COMPRISING A HORIZONTAL BOOM MOUNTED FOR PIVOTAL MOVEMENT IN A VERTICAL PLANE, A VERTICAL SPINDLE ON THE FREE END OF SAID BOOM, A SPIDER FRAME HAVING RADIAL ARMS CONNECTED TO A CENTRAL HUB ON SAID SPINDLE FOR ROTATION IN A HORIZONTAL PLANE, A CIRCULAR PLATFORM MOUNTED ON EACH OF SAID ARMS FOR ROTATION IN A HORIZONTAL PLANE ABOUT THE CENTER OF THE PLATFORM, SEATS FOR RIDERS MOUNTED AROUND THE PERIPHERIES OF SAID PLATFORMS, MEANS FOR RAISING AND LOWERING SAID BOOM TO SHIFT SAID SPIDER FRAME AND PLATFORMS BETWEEN HORIZONTAL AND INCLINED POSITIONS, A DRIVE SHAFT IN SAID SPINDLE, RUBBER TIRED WHEELS DRIVEN FROM SAID SHAFT AND ENGAGING THE PE- 